Perinatal colonization with extended-spectrum beta-lactamase-producing and carbapenem-resistant Gram-negative bacteria: a hospital-based cohort study.

BACKGROUND: Antimicrobial resistance (AMR) is a growing global health threat that contributes to substantial neonatal mortality. Bangladesh has reported some of the highest rates of AMR among bacteria causing neonatal sepsis. As AMR colonization among newborns can predispose to infection with these bacteria, we aimed to characterize the frequency of and risk factors for colonization of mothers and newborns during hospitalization for delivery. METHODS: We enrolled pregnant women presenting for delivery to a tertiary care hospital in Faridpur, Bangladesh. We collected vaginal and rectal swabs from mothers pre- and post-delivery, rectal swabs from newborns, and swabs from the hospital environment. Swabs were plated on agars selective for extended-spectrum-beta-lactamase producing bacteria (ESBL-PB) and carbapenem-resistant bacteria (CRB). We performed logistic regression to determine factors associated with ESBL-PB/CRB colonization. RESULTS: We enrolled 177 women and their newborns during February-October 2020. Prior to delivery, 77% of mothers were colonized with ESBL-PB and 15% with CRB. 79% of women underwent cesarean deliveries (C-section). 98% of women received antibiotics. Following delivery, 98% of mothers and 89% of newborns were colonized with ESBL-PB and 89% of mothers and 72% of newborns with CRB. Of 290 environmental samples, 77% were positive for ESBL-PB and 69% for CRB. Maternal pre-delivery colonization was associated with hospitalization during pregnancy (RR for ESBL-PB 1.24, 95% CI 1.10-1.40; CRB 2.46, 95% CI 1.39-4.37). Maternal post-delivery and newborn colonization were associated with C-section (RR for maternal CRB 1.31, 95% CI 1.08-1.59; newborn ESBL-PB 1.34, 95% CI 1.09-1.64; newborn CRB 1.73, 95% CI 1.20-2.47). CONCLUSIONS: In this study, we observed high rates of colonization with ESBL-PB/CRB among mothers and newborns, with pre-delivery colonization linked to prior healthcare exposure. Our results demonstrate this trend may be driven by intense use of antibiotics, frequent C-sections, and a contaminated hospital environment. These findings highlight that greater attention should be given to the use of perinatal antibiotics, improved surgical stewardship for C-sections, and infection prevention practices in healthcare settings to reduce the high prevalence of colonization with AMR organisms.

Prevalence, etiology and antibiotic resistance patterns of community-acquired urinary tract infections in Dhaka, Bangladesh.

Urinary tract infection (UTI) accounts for a significant morbidity and mortality across the world and is a leading cause for antibiotic prescriptions in the community especially in developing countries. Empirical choice of antibiotics for treatment of UTI is often discordant with the drug susceptibility of the etiologic agent. This study aimed to estimate the prevalence of community-acquired UTI caused by antibiotic resistant organisms. This was a cross-sectional study where urine samples were prospectively collected from 4,500 patients at the icddr,b diagnostic clinic in Dhaka, Bangladesh during 2016-2018. Urine samples were analyzed by standard culture method and the isolated bacteria were tested for antibiotic susceptibility by using disc diffusion method and VITEK-2. Descriptive statistics were used to estimate the prevalence of community acquired UTI (CA-UTI) by different age groups, sex, and etiology of infection. Relationship between the etiology of CA-UTI and age and sex of patients was analyzed using binary logistic regression analysis. Seasonal trends in the prevalence of CA-UTI, multi-drug resistant (MDR) pathogens and MDR Escherichia coli were also analyzed. Around 81% of patients were adults (≥18y). Of 3,200 (71%) urine samples with bacterial growth, 920 (29%) had a bacterial count of ≥1.0x105 CFU/ml indicating UTI. Women were more likely to have UTI compared to males (OR: 1.48, CI: 1.24-1.76). E. coli (51.6%) was the predominant causative pathogen followed by Streptococcus spp. (15.7%), Klebsiella spp. (12.1%), Enterococcus spp. (6.4%), Pseudomonas spp. (4.4%), coagulase-negative Staphylococcus spp. (2.0%), and other pathogens (7.8%). Both E. coli and Klebsiella spp. were predominantly resistant to penicillin (85%, 95%, respectively) followed by macrolide (70%, 76%), third-generation cephalosporins (69%, 58%), fluoroquinolones (69%, 53%) and carbapenem (5%, 9%). Around 65% of patients tested positive for multi-drug resistant (MDR) uropathogens. A higher number of male patients tested positive for MDR pathogens compared to the female patients (p = 0.015). Overall, 71% of Gram-negative and 46% of Gram-positive bacteria were MDR. The burden of community-acquired UTI caused by MDR organisms was high among the study population. The findings of the study will guide clinicians to be more selective about their antibiotic choice for empirical treatment of UTI and alleviate misuse/overuse of antibiotics in the community.

Spatiotemporal distribution of antimicrobial resistant organisms in different water environments in urban and rural settings of Bangladesh.

The spatial distribution of clinically important antibiotic resistant bacteria (ARB) and associated genes is important to identify the environmental distribution of contamination and 'hotspots' of antimicrobial resistance (AMR). We conducted an integrated survey of AMR in drinking water, wastewater and surface water (rivers and ponds) in three settings in Bangladesh: rural households, rural poultry farms, and urban food markets. Spatial mapping was conducted via geographic information system (GIS) using ArcGIS software. Samples (n = 397) were analyzed for the presence of extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-Ec), carbapenem-resistant E. coli (CR-Ec) and resistance genes (blaCTX-M-1,blaNDM-1). In rural households, 5% of drinking water supply samples tested positive for ESBL-Ec, and a high proportion of wastewater, pond and river water samples were positive for ESBL-Ec (90%, 76%, and 85%, respectively). In poultry farms, 10% of drinking water samples tested positive for ESBL-Ec compared to a high prevalence in wastewater, pond and river water (90%, 68%, and 85%, respectively). CR-Ec prevalence in household wastewater and pond water was relatively low (8% and 5%, respectively) compared to river water (33%). In urban areas, 38% of drinking water samples and 98% of wastewater samples from food markets tested positive for ESBL-Ec while 30% of wastewater samples tested positive for CR-Ec. Wastewaters had the highest concentrations of ESBL-Ec, CR-Ec, blaCTXM-1 and blaNDM-1 and these were significantly higher in urban compared to rural samples (p < 0.05). ESBL-Ec is ubiquitous in drinking water, wastewater and surface water bodies in both rural and urban areas of Bangladesh. CR-Ec is less widespread but found at a high prevalence in wastewater discharged from urban food markets and in rural river samples. Surveillance and monitoring of antibiotic resistant organisms and genes in waterbodies is an important first step in addressing environmental dimensions of AMR.

High prevalence of plasmid-mediated quinolone resistance (PMQR) among E. coli from aquatic environments in Bangladesh.

Fluro(quinolones) is an important class of antibiotic used widely in both human and veterinary medicine. Resistance to fluro(quinolones) can be acquired by either chromosomal point mutations or plasmid-mediated quinolone resistance (PMQR). There is a lack of studies on the prevalence of PMQR in organisms from environmental sources in Bangladesh. In this study, we investigated the occurrence of PMQR genes in E. coli from various water sources and analysed associations between multi-drug resistance (MDR) and resistance to extended spectrum ß-lactam antibiotics. We analysed 300 E. coli isolates from wastewaters of urban live-bird markets (n = 74) and rural households (n = 80), rural ponds (n = 71) and river water samples (n = 75) during 2017-2018. We isolated E. coli by filtering 100 ml of water samples through a 0.2µm cellulose membrane and incubating on mTEC agar media followed by identification of isolated colonies using biochemical tests. We selected one isolate per sample for detection of PMQR genes by multiplex PCR and tested for antibiotic susceptibility by disc diffusion. Clonal relatedness of PMQR-positive isolates was evaluated by enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). About 66% (n = 199) of E. coli isolates harbored PMQR-genes, predominantly qnrS (82%, n = 164) followed by aac(6')-lb-cr (9%, n = 17), oqxAB (7%, n = 13), qnrB (6%, n = 11) and qepA (4%, n = 8). Around 68% (n = 135) of PMQR-positive isolates were MDR and 92% (n = 183) were extended spectrum ß-lactamase (ESBL)-producing of which the proportion of positive samples was 87% (n = 159) for blaCTX-M-1' 34% (n = 62) for blaTEM, 9% (n = 16) for blaOXA-1, blaOXA-47 and blaCMY-2, and 2% (n = 4) for blaSHV. Further, 16% (n = 32) of PMQR-positive isolates were resistant to carbapenems of which 20 isolates carried blaNDM-1. Class 1 integron (int1) was found in 36% (n = 72) of PMQR-positive E. coli isolates. PMQR genes were significantly associated with ESBL phenotypes (p≤0.001). The presence of several PMQR genes were positively associated with ESBL and carbapenemase encoding genes such as qnrS with blaCTXM-1 (p<0.001), qnrB with blaTEM (p<0.001) and blaOXA-1 (p = 0.005), oqxAB and aac(6')-lb-cr with blaSHV and blaOXA-1 (p<0.001), qnrB with blaNDM-1 (p<0.001), aac(6')-lb-cr with blaOXA-47 (p<0.001) and blaNDM-1 (p = 0.002). Further, int1 was found to correlate with qnrB (p<0.001) and qepA (p = 0.011). ERIC-PCR profiles allowed identification of 84 of 199 isolates with 85% matching profiles which were further grouped into 33 clusters. Only 5 clusters had isolates (n = 11) with identical ERIC-PCR profiles suggesting that PMQR-positive E. coli isolates are genetically heterogeneous. Overall, PMQR-positive MDR E. coli were widely distributed in aquatic environments of Bangladesh indicating poor wastewater treatment and highlighting the risk of transmission to humans and animals.

Human Colonization with Extended-Spectrum Beta-Lactamase-Producing E. coli in Relation to Animal and Environmental Exposures in Bangladesh: An Observational One Health Study.

BACKGROUND: Human exposure to intensively farmed livestock is a potential risk for transmission of antibiotic-resistant bacteria (ARB) but few studies have assessed the relative role of animal vs. environmental sources of ARB in low-resource community settings. OBJECTIVES: We conducted an observational study to compare ARB colonization and antibiotic-resistant gene prevalence and abundance in humans with high or low exposure to poultry in rural households, commercial poultry farms, and urban markets in Bangladesh. METHODS: Extended-spectrum ß-lactamase (ESBL)-producing and carbapenem-resistant E. coli were quantified in feces from adults with high or low poultry exposure (n=100, respectively), poultry (n=200), drinking water (n=120), and wastewater (n=120) from 40 rural households, 40 poultry farms, and 40 urban markets. RESULTS: ESBL-producing E. coli (ESBL-EC) prevalence was 67.5% (95% CI: 61.0, 74.0) in samples from adults, 68.0% (95% CI: 61.5, 74.5) in samples from poultry, and 92.5% (95% CI: 87.7, 97.3) in wastewater samples. Carbapenem-resistant E. coli prevalence was high in market wastewaters [30% (95% CI: 15.0, 45.0)] but low in humans (1%) and poultry (1%). Human, poultry, and wastewater isolates shared common resistance genes: blaCTX-M-1, qnr, and blaTEM. Human colonization was not significantly associated with exposure to poultry or setting (rural, farm, or market). Ninety-five percent of commercial poultry farms routinely administered antibiotics. Susceptibility tests were significantly different in household vs. farm and market poultry isolates for four of seven antibiotic classes. In human isolates, there were no differences except aminoglycoside resistance (16.4% high vs. 4.4% low exposure, p=0.02). Urban market wastewaters and poultry samples had significantly higher concentrations of ESBL-EC (p<0.001) and blaCTX-M-1 (p<0.001) compared with samples from farms and rural households. DISCUSSION: ESBL-EC colonization was high in humans but not significantly associated with exposure to poultry. Bidirectional transmission of antibiotic resistance is likely between humans, poultry, and the environment in these community settings, underlining the importance of One Health mitigation strategies. https://doi.org/10.1289/EHP7670.

Occurrence and genetic characteristics of mcr-1-positive colistin-resistant E. coli from poultry environments in Bangladesh.

OBJECTIVES: Colistin is one of the last-resort antibiotics for the treatment of multidrug-resistant (MDR) Gram-negative bacterial infections. We determined the occurrence and characteristics of mcr-1-producing Escherichia coli obtained from live bird markets (LBMs), rural poultry farms (RPFs) and rural household backyard poultry environments (HBPs) in Bangladesh. METHODS: We tested 104 extended-spectrum ß-lactamase (ESBL)-producing E. coli isolated during 2017-2018 from poultry sources for colistin resistance. We analysed the resistant isolates for the mcr genes and characterized mcr-positive isolates for antibiotic susceptibility, antibiotic resistance genes, transmissible plasmids and clonal diversity. RESULTS: Of 104 isolates, 98 (94%) had MICcolistin ≥4 µg/mL and 14 (13.5%) were positive for mcr-1, of which 10 were from LBMs (n = 10), 3 were from RPFs and 1 was from an HBP. All 14 mcr-1 E. coli were resistant to third-generation cephalosporin and tetracycline, whereas 12 were resistant to fluoroquinolone and sulfamethoxazole, 10 were resistant to aminoglycosides and 3 were resistant to nitrofurantoin. Four isolates carried conjugative mcr-1 plasmid of 23-55 MDa in size. The 55 MDa plasmid found in two isolates carried additional resistant genes including blaCTX-M-group-1 and blaTEM-1 (ESBL), qnrB (fluoroquinolone), and rmtB (aminoglycoside). These plasmids belong to the IncF family with additional replicons: HI1 and N. Enterobacterial repetitive intergenic consensus-polymerase chain reaction revealed a heterogeneous banding pattern of mcr-1-positive isolates. CONCLUSION: We report a 13.5% prevalence of mcr-1-positive MDR E. coli in poultry faecal samples predominantly from LBMs in Bangladesh accentuating the need for safe disposal of poultry faeces and hygiene practices among people exposed to poultry.

High Genomic Diversity and Heterogenous Origins of Pathogenic and Antibiotic-Resistant Escherichia coli in Household Settings Represent a Challenge to Reducing Transmission in Low-Income Settings.

Escherichia coli is present in multiple hosts and environmental compartments as a normal inhabitant, temporary or persistent colonizer, and as a pathogen. Transmission of E. coli between hosts and with the environment is considered to occur more often in areas with poor sanitation. We performed whole-genome comparative analyses on 60 E. coli isolates from soils and fecal sources (cattle, chickens, and humans) in households in rural Bangladesh. Isolates from household soils were in multiple branches of the reconstructed phylogeny, intermixed with isolates from fecal sources. Pairwise differences between all strain pairs were large (minimum, 189 single nucleotide polymorphisms [SNPs]), suggesting high diversity and heterogeneous origins of the isolates. The presence of multiple virulence and antibiotic resistance genes is indicative of the risk that E. coli from soil and feces represent for the transmission of variants that pose potential harm to people. Analysis of the accessory genomes of the Bangladeshi E. coli relative to E. coli genomes available in NCBI identified a common pool of accessory genes shared among E. coli isolates in this geographic area. Together, these findings indicate that in rural Bangladesh, a high level of E. coli in soil is likely driven by contributions from multiple and diverse E. coli sources (human and animal) that share an accessory gene pool relatively unique to previously published E. coli genomes. Thus, interventions to reduce environmental pathogen or antimicrobial resistance transmission should adopt integrated One Health approaches that consider heterogeneous origins and high diversity to improve effectiveness and reduce prevalence and transmission.IMPORTANCEEscherichia coli is reported in high levels in household soil in low-income settings. When E. coli reaches a soil environment, different mechanisms, including survival, clonal expansion, and genetic exchange, have the potential to either maintain or generate E. coli variants with capabilities of causing harm to people. In this study, we used whole-genome sequencing to identify that E. coli isolates collected from rural Bangladeshi household soils, including pathogenic and antibiotic-resistant variants, are diverse and likely originated from multiple diverse sources. In addition, we observed specialization of the accessory genome of this Bangladeshi E. coli compared to E. coli genomes available in current sequence databases. Thus, to address the high level of pathogenic and antibiotic-resistant E. coli transmission in low-income settings, interventions should focus on addressing the heterogeneous origins and high diversity.

Quantification of Airborne Resistant Organisms With Temporal and Spatial Diversity in Bangladesh: Protocol for a Cross-Sectional Study.

BACKGROUND: Antimicrobial resistance is a widespread, alarming issue in global health and a significant contributor to human death and illness, especially in low and middle-income countries like Bangladesh. Despite extensive work conducted in environmental settings, there is a scarcity of knowledge about the presence of resistant organisms in the air. OBJECTIVE: The objective of this protocol is to quantify and characterize the airborne resistomes in Bangladesh, which will be a guide to identify high-risk environments for multidrug-resistant pathogens with their spatiotemporal diversity. METHODS: This is a cross-sectional study with an environmental, systematic, and grid sampling strategy focused on collecting air samples from different outdoor environments during the dry and wet seasons. The four environmental compartments are the frequent human exposure sites in both urban and rural settings: urban residential areas (n=20), live bird markets (n=20), rural households (n=20), and poultry farms (n=20). We obtained air samples from 80 locations in two seasons by using an active microbial air sampler. From each location, five air samples were collected in different media to yield the total bacterial count of 3rd generation cephalosporin (3GC) resistant Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, vancomycin-resistant Enterococci and methicillin-resistant Staphylococcus aureus. RESULTS: The study started in January 2018, and the collection of air samples was completed in November 2018. We have received 800 air samples from 80 study locations in both dry and wet seasons. Currently, the laboratory analysis is ongoing, and we expect to receive the preliminary results by October 2019. We will publish the complete result as soon as we clean and analyze the data and draft the manuscript. CONCLUSIONS: The existence of resistant bacteria in the air like those producing extended-spectrum beta-lactamases, carbapenem-resistant Enterobacteriaceae, vancomycin-resistant Enterococci, and methicillin-resistant Staphylococcus aureus will justify our hypothesis that the outdoor environment (air) in Bangladesh acts as a reservoir for bacteria that carry genes conferring resistance to antibiotics. To our knowledge, this is the first study to explore the presence of superbugs in the air in commonly exposed areas in Bangladesh. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/14574.

Risk Factors for Detection, Survival, and Growth of Antibiotic-Resistant and Pathogenic Escherichia coli in Household Soils in Rural Bangladesh.

Soils in household environments in low- and middle-income countries may play an important role in the persistence, proliferation, and transmission of Escherichia coli Our goal was to investigate the risk factors for detection, survival, and growth of E. coli in soils collected from household plots. E. coli was enumerated in soil and fecal samples from humans, chickens, and cattle from 52 households in rural Bangladesh. Associations between E. coli concentrations in soil, household-level risk factors, and soil physicochemical characteristics were investigated. Susceptibility to 16 antibiotics and the presence of intestinal pathotypes were evaluated for 175 E. coli isolates. The growth and survival of E. coli in microcosms using soil collected from the households were also assessed. E. coli was isolated from 44.2% of the soil samples, with an average of 1.95 log10 CFU/g dry soil. Soil moisture and clay content were associated with E. coli concentrations in soil, whereas no household-level risk factor was significantly correlated. Antibiotic resistance and pathogenicity were common among E. coli isolates, with 42.3% resistant to at least one antibiotic, 12.6% multidrug resistant (≥3 classes), and 10% potentially pathogenic. Soil microcosms demonstrate growth and/or survival of E. coli, including an enteropathogenic extended-spectrum beta-lactamase (ESBL)-producing isolate, in some, but not all, of the household soils tested. In rural Bangladesh, defined soil physicochemical characteristics appear more influential for E. coli detection in soils than household-level risk factors. Soils may act as reservoirs in the transmission of antibiotic-resistant and potentially pathogenic E. coli and therefore may impact the effectiveness of water, sanitation, and hygiene interventions.IMPORTANCE Soil may represent a direct source or act as an intermediary for the transmission of antibiotic-resistant and pathogenic Escherichia coli strains, particularly in low-income and rural settings. Thus, determining risk factors associated with detection, growth, and long-term survival of E. coli in soil environments is important for public health. Here, we demonstrate that household soils in rural Bangladesh are reservoirs for antibiotic-resistant and potentially pathogenic E. coli strains and can support E. coli growth and survival, and defined soil physicochemical characteristics are drivers of E. coli survival in this environment. In contrast, we found no evidence that household-level factors, including water, sanitation, and hygiene indicators, were associated with E. coli contamination of household soils.